A touchscreen comprises two distinct elements and functions: a display for displaying information and an input that is activated by touching the display. By incorporating a touchscreen into an electronic device, the electronic device can be made smaller and, often, less expensive by minimizing the number and size of other user inputs on the electronic device. In the recent past, touchscreen prices have dropped sufficiently that a touchscreen can cost-effectively be included in a wide variety of electronic devices having an even wider variety of applications. Electronic devices that comprise a touchscreen interface can include a desktop computer, a tablet computer, a laptop computer, a netbook, a personal digital assistant, a mobile phone, a Smart Phone, a digital camera, a digital music player, a digital camcorder, a digital picture frame, an electronic book reader (e-book), a bank automated teller machine (ATM), an automated retail self-checkout system, and retail checkout system for using a debit or credit card. These are but a few of the many electronic devices and applications for a touchscreen interface.
In normal use, the viewable area of a touchscreen is obscured by a user's hand as the user makes an input on the touchscreen with her hand. For example, the Apple® iPad® and Apple® iPhone® feature a touchscreen input method where a user touches the screen with two fingers, simultaneously, and draws his fingers closer together or spreads them farther apart to zoom out and zoom in, respectively, to a view of a picture on the touchscreen display. Another touchscreen input method is the user making a swiping motion with a finger across the surface of the touchscreen in order to move the displayed information laterally on the touchscreen. Other touchscreen user inputs include touching, tapping, or double tapping an icon displayed on the touchscreen display to select or activate the icon, including an icon representing a key of a keyboard, and sliding a fingertip continuously across the touchscreen to scroll the display in the direction of the fingertip motion. When a user makes any of these touchscreen inputs, the user's hand obstructs the user's view of the touchscreen display area.
A user can have an unobstructed view of a touchscreen display by using another input device, other than the touchscreen, such as a mouse, a trackball, a touchpad, a keyboard, a stylus pen, or a motion tracking device such as the Microsoft® Kinect®. Each of these solutions requires that the electronic device have hardware additional to the touchscreen. For modern portable electronic devices, an external mouse, a keyboard, or a trackball is not practical because the user must carry this extra hardware, connect it before it can be used, and the user must use the portable electronic device in a location conducive to the hardware, such as a flat surface. Further, a keyboard lacks the input flexibility offered by a touchscreen and is slow and cumbersome to use as compared to a touchscreen. A trackball offers fixed, poor resolution and cannot support multi-touch input gestures such as those described above for a touchscreen. A motion tracking device requires extensive additional hardware and software, and currently is unable to detect finger-level gesture tracking with acceptable accuracy. A stylus pen offers a single point of interaction and cannot support multi-touch input gestures. Further, the stylus pen is small and easily lost or misplaced. The stylus pen also does not solve the problem that the input device, a stylus pen or the user's fingers, obstructs the view of the touchscreen display when the user makes an input on the touchscreen.
Currently, user input on portable electronic devices is often entered using a touchscreen display. Performing user input with a touchscreen display obscures the user's view of the display unless he moves his hand away from the display with each user input. It is inconvenient to relocate one's hand at each user input to see the display screen, and it is further inconvenient to obscure the vision of the display by further user input.